1. Field of the Invention
The present invention relates generally to ladders and, more specifically, to an extension stepladder with tripod forming support rails. The three legs of the tripod are the two support rails and the ladder which is described as one leg.
The stepladder of the present invention consists of a ladder portion that is comprised of rungs and includes two ladder side rails, and a support portion that includes two telescoping rails that provide means for stabilizing the ladder.
The telescoping support rails are interconnected to each other and to the ladder side rails by lockable rigid spanner arms. When in use, the spreader arms are locked in an open position providing means to form a tripod formation between the rails while additionally limiting the angle of spread between the ladder rails and the support rails.
When not in use, the spanner arms are pivotally rotated to allow the support legs to close and retract toward the ladder rails forming a compact and transportable ladder assembly.
The tripod style extension stepladder of the present invention provides means for improved safety, increased capability and convenience. The tripod legs maximize the base spans of the stepladder by extending divergently from the ladder portion creating a large base support. The higher the ladder extension the larger the base spans on the floor so that the user does not have to compromise the stability at any elevation setting. Each of the support rails is independently telescopic to allow for use on uneven surfaces.
Additionally, the stepladder of the present invention also provides a retractable support rail at the top of the ladder rails to provide means for additional usable working height. Since the user can easily place themselves out of balance when both hands are off of the stepladder creating a safety hazard, a safety belt is provided on the handle for additional support.
The tripod stepladder of the present invention provides extendable retractable support legs having rigid spanners forming a tripod structural support member to prevent movement of the legs relative to each other when in the extended position. Furthermore, additional safety features are incorporated comprising telescopic support legs for use on an uneven base surface, an extendable hand rail at the top of the ladder and a safety belt, with both providing safety and a secure working environment for the user.
A series of apertures with lock key fasteners in each of the support legs provide means for the user to securely position the legs at a desired length. The lock key fastener includes a locking pin that engages an aperture in the corresponding leg to secure the desired position.
2. Description of the Prior Art
There are other extension ladders and stepladders that provide improved stabilization. Typical of these is U.S. Pat. No. 46,105 issued to Hayes on Jan. 31, 1865.
Another patent was issued to Bowser on Feb. 19, 1895 as U.S. Pat. No. 534,463. Yet another U.S. Pat. No. 1,670,653 was issued to Cummins on May 22, 1928 and still yet another was issued on Aug. 22, 1961 to Wojtowicz as U.S. Pat. No. 2,997,127.
Another patent was issued to Conrad on Apr. 28, 1970 as U.S. Pat. No. 3,508,628. Yet another U.S. Pat. No. 3,856,112 was issued to Stewart on Dec. 24, 1974. Another was issued to Beach on Feb. 28, 1984 as U.S. Pat. No. 4,433,754 and still yet another was issued on Jan. 17, 1989 to Margolies as U.S. Pat. No. 4,798,262.
Another patent was issued to High, et al. on Jan. 7, 1997 as U.S. Pat. No. 5,590,739. Yet another U.S. Pat. No. 6,533,071 issued on Mar. 18, 2003 to Smith. Another European Patent was issued to Klenk on Apr. 27, 1981 as EP0039078. WIPO Patent Publication No. WO 00/32900 was filed by Laug and published on Jun. 8, 2000.